Polymer based electrooptic devices can be used to provide high speed modulation of optical signals at relatively low voltages. While polymers as deposited generally do not exhibit the linear electrooptic effect, application of suitable electric fields at suitable temperatures establishes polymer configurations that exhibit the electrooptic effect, typically as associated with symmetry group mm∞ so as to have nonzero electrooptic coefficients r33 and r13. Polymers can be poled in this way so that electrooptic coefficients on the order of 100 pm/V are produced. Polymers can be deposited on a variety of substrates, including semiconducting substrates such as silicon so that optical waveguide devices and electronic devices can be integrated on a common substrate.
One drawback of polymer based waveguide devices is the necessity of inducing the electrooptic effect in a polymer layer. This “poling” process must generally be performed on an otherwise virtually completed device. Thus, for example, defective polymer layers may not be identified until the end of processing, so that process steps are wasted. In addition, while devices are subject to suitable poling conditions during fabrication, the extent of poling throughout such devices cannot be determined until poling is completed. Additional approaches to evaluating and fabricating waveguide devices that include electrooptic polymer layers are needed.